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diff --git a/db/docs/ref/bdb_sentity/intro.html b/db/docs/ref/bdb_sentity/intro.html deleted file mode 100644 index 4d8e3de0b..000000000 --- a/db/docs/ref/bdb_sentity/intro.html +++ /dev/null @@ -1,63 +0,0 @@ -<!--$Id: intro.html,v 1.1 2003/12/15 21:43:45 jbj Exp $--> -<!--Copyright 1997-2003 by Sleepycat Software, Inc.--> -<!--All rights reserved.--> -<!--See the file LICENSE for redistribution information.--> -<html> -<head> -<title>Berkeley DB Reference Guide: Serializable Entity - One serializable class for entities and values</title> -<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> -<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> -</head> -<body bgcolor=white> -<a name="2"><!--meow--></a> -<table width="100%"><tr valign=top> -<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Java API Tutorial - Serializable Entity</dl></h3></td> -<td align=right><a href="../bdb_tuple/sorted.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../bdb_sentity/class.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p> -<h3 align=center>Serializable Entity - One serializable class for entities and values</h3> -<p>In the prior examples that used entities (Entity and Tuple) you may have -noticed the redundancy between the serializable value classes and the entity -classes. An entity class by definition contains all properties of the value -class as well as all properties of the key class.</p> -<p>When using serializable values it is possible to remove this redundancy -by changing the entity class in two ways:</p> -<p><ul type=disc> -<li>Make the entity class serializable, so it can be used in place of -the value class. -<li>Make the key fields transient, so they are not redundantly stored in -the record. -</ul> -<p>The modified entity class can then serve double-duty: It can be -serialized and stored as the record value, and it can be used as the entity -class as usual along with the Java collections API. The <b>PartValue</b>, -<b>SupplierValue</b> and <b>ShipmentValue</b> classes can then be -removed.</p> -<p>The example program illustrates:</p> -<p><ul type=disc> -<li><a href="class.html">Using transient fields in an entity class</a> -<li><a href="binding.html">Using transient fields in an entity binding</a> -<li><a href="remove.html">Removing the redundant value classes</a> -</ul> -<p>Transient fields are defined in Java as fields that are not stored in -the serialized form of an object. Therefore, when an object is deserialized -the transient fields must be explicitly initialized. Since the entity binding -is responsible for creating entity objects, it is the natural place to -initialize the transient key fields.</p> -<p>Note that it is not strictly necessary to make the key fields of a -serializable entity class transient. If this is not done, the key will simply -be stored redundantly in the record's value. This extra storage may or may not -be acceptable to an application. But since we are using tuple keys and an -entity binding class must be implemented anyway to extract the key from the -entity, it is sensible to use transient key fields to reduce the record size. -Of course there may be a reason that transient fields are not desired; for -example, if an application wants to serialize the entity objects for other -purposes, then using transient fields should be avoided.</p> -<p>The complete source -of the final version of the example program is included in the Berkeley DB -distribution.</p> -<table width="100%"><tr><td><br></td><td align=right><a href="../bdb_tuple/sorted.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../bdb_sentity/class.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p><font size=1><a href="../../sleepycat/legal.html">Copyright (c) 1996-2003</a> <a href="http://www.sleepycat.com">Sleepycat Software, Inc.</a> - All rights reserved.</font> -</body> -</html> |